Filter



Sep 28, 1943-` w. B. REPPMANN FILTER Filed May l, 1940 FIC-3.2

appreciated'by those skilled in thel art.

Patented Sept.` 28, 1943 wilhelm Benjamin neppmsnn, on. Netherland.; vested in the Alien Property Custodian a Application May l, 1940, Serial No. 332,822

In the Netherlands May 15. 1939 Claims.d (Cl. E10- 177) This invention relates to improvements in filters.

In filtering processes it often occurs that the sediment deposited on the carrier or filtering medium. for instance nltering cloth, stillcontains much liquid. Till now it has been usual to remove the sediment from the filter and then to recuperate the liquid out of this sediment.

However, this process is rather intricate and moreover much of the liquid is lost by doing so.

The general object of the present invention is a convenient filter. construction by means of which it is possible tc'obtain a better separation of the nitrate out of the raw material.

s further object is s nner in which the whole of the filter surface is constantly used.

Another object is -to provide for an easy and quick cleaningl of the filter.

Still another object is to arrange a large nltering area within a small space and to allow the filtering operation to take place under pressure in a closed space.

With the above and other objects in view the novel and improved features, constructions and combinations of parts hereinafter described, and particularly pointed out in the claims. the advantages of which will be readily understood and In the drawing:

'in ma. s.

Similar parts are represented by thesame reference characters.

Fig. l represents the preferred embodiment of vthe invention. The casing I is preferably cylin-a drical although other shapes are4 possible. The cylindrical shape is preferred because it is most ring i. The rawrnaterial isv supplied through the inlet 1 and the clear liquid is exhausted through the outlet l. The piston rod l is guided detail in the Figures 3 and 4. The plates are interconnected and spaced by means of tapes ao Figs. l and 2 are vertical sectional views suitable for cooperating with a steam or liquid Jacket. such that materials can also be ltered in a heated condition. The carrier I. which gendrical and usually is already in a folded condition when filtering, in order to provide for a large I filter surface. This'ciurierl is attached at one of its ends to a piston I by means of an elastic ring t and at its other end to the cover l of erally consists of a suitable cloth is likewise cylinv, filter plate -is represented which 'satisfies the the i, likewise by means of an elastic es above-mentioned requirement and is moreover or ribbons i I and i2. which keep the plates at the required mutual distances, when the piston 2 is moved towards itstop position in Fig. l.

Keeping the filter plates in the required position can also be effected in other manners, for instance by arranging springs between the plates, the said springs having when being compressed a height equal to the thickness of a laver of pressed out sediment. The connection by means of the tapes however, is'very easy and effective. Y

lIi'or removing the sediment and cleaning the filter it will be sufficient to loosen the cover I from the casing and tostretch the carrier 3. The illter cake is then easily broken up and removed from the carrier s.

The filter plates I0 can be guided otherwise than .by means of the piston rod I and they can also be arranged in another manner. This is illustrated invFig. 2. The filter plates I0 in this case lare ring-shaped and extend from the exterior into the folds of the lter cloth l. In this Y the same way as the slats-of a Venetian blind.

The inlet of the raw material is arranged centrally at 1 and the outlet of the flltrated liquid is at 8.

On account of the piston rod I being arranged outside the casing more space is left in the interior hereof so that a larger area of filtering cloth can'be arranged in the filter. When pressing 'out the liquid out of the sediment the inletopening 1 is closed and the 'piston 2 is pressed downwardly. For cleaning the filter of its sediment the cover 5 is taken on and the casing i is also taken off so that the filtering cloth is sediment can be easily removed from the interior,

- thereof. v

The plates lil must be adapted to` let the liquid pass in an easy manner. To this end they are provided with a large number of slits.

In Figs. 3 and 4 a preferred embodiment of a resistant and reliable. Such a plate-is composed of two plates I and I0" each of which is provided with a set of slits, the said plates being, however, secured to each other in such a manner, that the slits cross another at an angle of e. g. 90 or less.

The interesting` feature of this plate is that liquid can flow through the plate from either side thereof, thereby followingy a zig-zag path. The plates l0' and I0" can be made identical and they are easier to manufacture than plates having radial slits, which moreover are not so resistant as those according to Figs. 3 and 4 on account of the slits extending up to the periphery.

In Figs. 5 and 6 is represented a preferred construction of a lter cloth or carrier. This carrier comprises a series of ring-shaped parts I6.

which two by two are connected at their inner edges l1 by a stitch line` and which at the pe'- riphery are laid around the edges ofthe filter plates' I0. The outer peripheral line of these arranged in the interior and in thel folds of the carrier, and ilexible means for spacing and guiding said plates, the inlet being connected with the space between the carrier and the casing andl the outlet being connected with the space in the cylindrical carrier.

2. A lter comprising a casing having an inletfor material to be ltered and an outlet for the `ltrate, a zig-zag foldable cylindrical lter-fabric parts is provided with a seam'iil in which a draw cord I8 is inserted. .In Fig. 6 such an individual element is represented when it is spread out at the moment of being laid around the edge of a filter plate and of course the draw cord is kept loose. After the cloth has been laid around the edge oi' a lter plate the draw cord is tightened, so

that the cloth is held readily in place. At the edge of eachillter plate two edges of the cloth element are laid above one another, as shown in Fig. 5. Such a carrier can be readily mounted and demounted.

It is to be understood that the invention is not limited to the particular constructions and arrangements of parts of the illustrated embodiment oi' the invention, but that the invention may be embodied 'in other forms within' the scope of the claims.

Having explained thenature and objects of the invention and having speciilcally described conjsgructions embodying the invention, what I claim 1. A filter-comprising a casing having an inlet for material to be-ltered and an outlet for the filtrate, a zig-zag foldable cylindrical lter-fabric carrier of :illter fabric for the filter' sediment in -said casing, members to which the ends of the carrier are secured in a liquid tight manner, said members being movable towards each other for pressing out ,the carrier and the sediment deposited thereon, disc-shaped perforated plates carrierof lter fabric for the lter sediment in said casing, members tdwhich theends of the carrier are'secured in a liquid tight manner, said members being movable towards each other for pressing out theA carrier and the sediment deposited thereon, disc-shaped perforated plates arranged in the folds of said carrier and in the space between the carrier and the casing, flexible means for spacing and guiding said plates. the

inlet being connected with the space in the cylindrical carrier and the outlet being connected with the spacebetween the carrier and the cas- 3. A filter comprising a casing having an inlet for material to be filtered and an outlet for the ltered fluid, a zig-zag foldable carrier of filter fabric, relatively movable end closure members for the carrier, and filter plates provided with two sets of slits arranged at an angle, the slits being situated in diierent planes in such a manner that the slits of one set are in communication with those of the other set, the said plates being arranged in folds of` the carrier, means for guiding the plates and means for moving the plates relative to each other. f

4. A illter comprising a casing closed at the ends, having an inlet for material to be'ltered and an outlet for the filtrate, a pleated carrier of lter fabric arranged in said casing and interv,inner edges of said rings being connected together by a stitch line and draw cords-arranged in the outer edges.

WILHELM BENJAMIN REPPMANN. 

